Problem:
Does there exist a triangle in which two sides are integer multiples of the median to that side? Does there exist a triangle in which every side is an integer multiple of the median to that side?
Problem:
Does there exist a triangle in which two sides are integer multiples of the median to that side? Does there exist a triangle in which every side is an integer multiple of the median to that side?
Solution:
Answer yes, no
The obvious approach is to make the triangle isosceles. So suppose the sides are , , . Then the length of a median to one of the sides length satisfies: . The simplest possibility is to take , so . Thus if , .
Suppose we have a triangle , with medians , , , and , , all integers. If , then . If , then is obtuse, so at least two of the medians must be equal to the corresponding sides. So wlog we have , . Subtracting, , so . Hence . So the third median has length where , so , which is not integral. Contradiction.